By buying an index fund, investors can approximate the average market return. But if you buy good businesses at attractive prices, your portfolio returns could exceed the average market return. For example, Amplify Energy Corp. (NYSE:AMPY) shareholders have seen the share price rise 80% over three years, well in excess of the market return (11%, not including dividends).

So let's investigate and see if the longer term performance of the company has been in line with the underlying business' progress.

See our latest analysis for Amplify Energy

To quote Buffett, 'Ships will sail around the world but the Flat Earth Society will flourish. There will continue to be wide discrepancies between price and value in the marketplace...' By comparing earnings per share (EPS) and share price changes over time, we can get a feel for how investor attitudes to a company have morphed over time.

Amplify Energy became profitable within the last three years. So we would expect a higher share price over the period.

The graphic below depicts how EPS has changed over time (unveil the exact values by clicking on the image).

We consider it positive that insiders have made significant purchases in the last year. Having said that, most people consider earnings and revenue growth trends to be a more meaningful guide to the business. This free interactive report on Amplify Energy's earnings, revenue and cash flow is a great place to start, if you want to investigate the stock further.

A Different Perspective

Amplify Energy shareholders are down 0.7% for the year, but the market itself is up 23%. Even the share prices of good stocks drop sometimes, but we want to see improvements in the fundamental metrics of a business, before getting too interested. Longer term investors wouldn't be so upset, since they would have made 4%, each year, over five years. If the fundamental data continues to indicate long term sustainable growth, the current sell-off could be an opportunity worth considering. I find it very interesting to look at share price over the long term as a proxy for business performance. But to truly gain insight, we need to consider other information, too. Case in point: We've spotted 1 warning sign for Amplify Energy you should be aware of.

There are plenty of other companies that have insiders buying up shares. You probably do not want to miss this free list of undervalued small cap companies that insiders are buying.

Please note, the market returns quoted in this article reflect the market weighted average returns of stocks that currently trade on American exchanges.

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This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.